Do I need a neutral white wire to install a 220v GFCI breaker in the main panel ?

Currently have 220v, 2 pole red hot, black hot and green ground in the circuit running pool pump timer and pump.

Or can I use the green wire as neutral? I believe the answer is no.

Please advise. Thank you.

2 Answers 2


No, you do not need a neutral "load" wire if you're running only 240V load. The GFCI will detect any imbalance between the two phases and trip if one occurs. See picture below.

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The green wire can never be used for anything but a ground.


This is straightforward.

For a 240V GFCI device, it will have a neutral pigtail. That must be hooked up, for the purpose of powering the GFCI device itself.

However once that's hooked up, you are welcome to attach a 240V circuit hot-hot only.

Remember white wires used as hot need to marked with tape to indicate they are hots. Otherwise someone might put them on the GFCI neutral!


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